NLSP | CCNP CIT Exam Cram 2 (Exam Cram 642-831)

The NetWare Link Services Protocol (NLSP) is an advanced link-state routing protocol developed by Novell for use in Novell NetWare. NLSP has several advantages over IPX RIP. NLSP enables you to remove IPX SAP advertisements from an identified network segment. NLSP then handles network updates. The protocol reduces both IPX RIP and SAP advertisements by sending updates on changes to a database, rather than by sending the complete table every 60 seconds. This is another routing protocol that sends an update only if a change in the network topology has occurred, unless no activity takes place for two hours, after which time the NLSP-enabled interface will send an update to all of its neighbors.

Enabling NLSP

To enable NLSP, use the ipx nlsp enable command on each interface connecting to segments that need to have NLSP enabled. You must then identify the NLSP area address.

You need to configure a couple of prerequisites when using NLSP. The area-address area mask command is used to define which IPX addresses are part of a particular area. You can use zero for area address and zero for the mask. Using zeros indicates that all area addresses are to be included in this area.

NLSP requires use of the ipx internal-network command to identify the IPX internal network.

When configuring NLSP, we must first enable IPX routing by using the ipx internal-network command to identify the IPX internal network for the router. Next , configure both active the default encapsulation (HDLC on Serial 0, novell- ether on Ethernet 0) on the interface, and identify the networks connected to each interface. The following shows an example:

 DCS2514#  config terminal  DCS2514(config)#  ipx routing  DCS2514(config)#  ipx internal-network d  DCS2514(config)#  ipx router nlsp  DCS2514(config-ipx-router)#  area-address 0 0  DCS2514(config)#  interface serial0  DCS2514 (config-if)#  ipx network 100  DCS2514(config-if)#  ipx nlsp enable  DCS2514 (config-if)#  interface ethernet0  DCS2514 (config-if)#  ipx network 300  DCS2514(config-if)#  exit  DCS2514(config)#

NLSP Troubleshooting Commands

In order to troubleshoot the NLSP protocol, you can use the following show commands to verify the configuration is correct and that NLSP is functioning correctly:

show ipx route
show ipx servers
show ipx nlsp neighbors
show ipx nlsp database

In the next sections, let's take a look at each command and its output.

show ipx route Command

When you configure NLSP, the routing table output produced by using the show ipx route command shows a serial route, as in this example:

 DCS2514#  show ipx route  Codes: C - Connected primary network,        c - Connected secondary network        S - Static, F - Floating static, L - Local        (internal), W - IPXWAN        R - RIP, E - EIGRP, N - NLSP, X - External,        A - Aggregate        s - seconds, u - uses 3 Total IPX routes. Up to 1 parallel paths and 16 hops allowed. No default route known. L 400 is the internal network C 500 (HDLC), Serial0 C 200 (NOVELL-ETHER), Ethernet0

show ipx servers Command

You can use the show ipx servers command to view all the known routes to the servers learned by the router. The following is an example of using the show ipx servers command:

 DCS2514#  show ipx servers  Codes: S - Static, P - Periodic, E - EIGRP, N - NLSP,        H -Holddown, + = detail 2 Total IPX Servers Table ordering is based on routing and server info    Type  Name        Net  Address       Port Route  Hops Itf N  4     File&Print1 100.0000.0000.0001:0000 12/02  2    Se0 N  4     CAD1        100.0000.0000.0002:0000 12/02  2    Se0

show ipx nlsp neighbors Command

The show ipx nlsp neighbors command can be used to display all the known NLSP neighbors, which are NLSP resources that are directly connected to the router's interfaces. The following is an example of using the show ipx nlsp neighbors command as well as the output.

 DCS2621#  show ipx nlsp neighbors  NLSP Level-1 Neighbors: Tag Identifier = notag System Id Interface State Holdtime Priority  Circuit Id DCS2514  Se0       Up    55       0         04 DCS2621 has one NLSP neighbor, DCS2514. By adding the detail command, the output includes the IPX internal network number and the uptime. DCS2621#  show ipx nlsp neighbors detail  NLSP Level-1 Neighbors: Tag Identifier = notag System Id Interface State Holdtime Priority Circuit Id DCS2514 Se0       Up    43       0        04 IPX Address: 100.0000.0000.0001 IPX Areas: 00000000/00000000 Uptime: 01:13:09

show ipx nlsp database Command

The show ipx nlsp database command provides information on the NLSP processes, as in the following example:

 DCS2514#  show ipx nlsp database  NLSP Level-1 Link State Database LSPID           LSP Seq      Num LSP      Checksum LSP Holdtime ATT/P/OL DCS2501.00-00 * 0x0000043B   0x2C77       203                   0/0/0 DCS2514.04-00 * 0x000001D2   0x1A2D       440                   0/0/0 DCS2514.00-00   0x00000023   0x1CAA       2311                  0/0/0 DCS2621.03-00   0x00000A22   0x9DE9       892                   0/0/0 DCS2621.00-00   0x00000342   0xCD9B       821                   0/0/0 RSM1.00-00      0x00000221   0x2C99       16                    0/0/0 RSM.02-00       0x00000361   0x235B       16                    0/0/0

The preceding output shows each entry in the NLSP database that is using a link state protocol identifier (LSPID). This column contains a value including a system identifier, a pseudonode circuit identifier, and a fragment number. The link state protocol (LSP) is the foundation of NLSP, and the show ipx nlsp database command reports significant information, including the last sequence number, the checksum, and the LSP holdtime. The holdtime indicates when the information will be flushed from the database, if a Hello packet or update is not received. The ATT/P/OL field is used by the Cisco Technical Assistance Center (TAC) for troubleshooting. This field is used to describe the Layer 2 attachments and the overload bits. The P bit (partition) indicates whether or not a partition is used.